Neurath’s protocol statements revisited: sketch of a theory of scientific testimony

This paper puts forward a significant revision of the interpretation of Neurath’s proposal for the form and content of so-called protocol sentences that was given by the author some years ago. Importantly, it eschews the ambition to give necessary and sufficient conditions for Neurath’s explicandum and instead aims merely to provide a characterisation of central cases. Even more importantly, it refocusses the explicandum from observation statements generally to observation reports and casts Neurath’s proposal in the form of an incipient theory of scientific testimony, in particular, testimony about observational evidence. In light of this analysis the paper then links Neurath’s proposal to current debates about the viability of Sellars’s anti-foundationalism and explores the nature of testimony and the justification of perceptual knowledge in science and everyday life.